The authors demonstrate the production of low loss enhanced index contrast waveguides by reactive ion etching of IPG (TM) polysiloxane thin films. The use of a silica mask and CHF3/O-2 etch gas led to large etch selectivity between the silica and IPG (TM) of >20 and etch rates of >100 nm/min. This work indicates that compact optical circuits could be successfully fabricated for telecommunication applications using polysiloxane films.